1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a color-filterless liquid crystal display device with unchanged display quality.
2. Description of Related Art
With a rapid development of monitor types, novel and colorful monitors with high definition, e.g., liquid crystal displays (LCDs), are indispensable components used in various electronic products such as mobile phones, personal digital assistants, digital cameras, desktop computers and notebook computers.
FIG. 1 shows a schematic diagram of a conventional liquid crystal display device. The liquid crystal display device 10 is assembled by several main components, such as light sources 12 (e.g., cold cathode fluorescent lamps, hot cathode fluorescent lamps, and light emitting diodes), a reflector 14, a light guide plate 16, a diffusion sheet 18, a polarization film 20, and a liquid crystal cell 22. The liquid crystal cell 22 comprises a substrate 24, a color filter 26 and a plurality of pixels, and each pixel is composed of sub-pixels indicating three primary colors of red, green and blue, respectively.
The light guide plate 16 may, after receiving a light emitted from the light source 12, guide the light to scatter as a uniform area light. On the other hand, the reflector 14 positioned on one side of the light guide plate 16, reflects the light emitted toward itself back to the light guide plate 16, to avoid light leakage; thereby increasing the efficiency of emitted light. The light emitted from the light guide plate 16, after being uniform through the diffusion sheet 18 to enhance brightness and uniformity, is emitted into the liquid crystal cell 22. However, an alignment of the liquid crystal molecules corresponding to each sub-pixel within the liquid crystal cell 22, is varied based on the voltage provided by the driving chip, to adjust the luminous flux when light is passing through. Furthermore, the light emitted from the light source 12 is a monotonous white light, and thus the color filter 26 of the liquid crystal display device 10 includes the light filter regions 26a, 26b and 26c, corresponding to sub-pixels of three primary colors of red, green and blue, respectively, wherein light of various colors is generated after the light passes through the liquid crystal molecules.
The color filter is formed on a glass substrate by using organic materials of three primary colors of red, green and blue within each sub-pixel. However, the cost of color filters is the highest among those of all indispensable components for a liquid crystal display device. In such case, to reduce the use of color filters may be favorable to lower the total production cost of liquid crystal display devices.